Eddie 70

I have been troubleshooting my car for code 1 now off and on for about 2 weeks now on the weekends. The car is not being driven but for short trips around town. It runs fine but it idles fast. When I jumpered the connector, I saw one flash. I looked that up and saw O2. So that is where I have been focused. This morning I was looking at the codes online and saw there is a code 10. Then it hit me, my code was one long flash.......IAT. Crap.

Now, I need to get started oin the IAT. Just for kicks since I am new to the Honda stuff and this is my first. Would a bad IAT cause the car to idle at higher than normal speeds? What are some of the symptoms of a bad IAT?
When I first got the car it had a bad stumble that I finally figured out. Two of the electrical connectors were crossed and one of those was the IAT. Would this have caused the IAT to go bad?

I am going to start looking at the IAT shortly and get this thing back to normal. Any help with my questions is greatly appreciated.

lazlong

Short answer- yes.

Eddie 70

I just checked and I have 5V coming to the IAT. I measured the IAT resistance and it is approximately 1 ohm with the car cold. It has been setting all night. I read the factory service manual and it says from .4-4k ohms. Sounds to me like I have a bad IAT since it is reading so low. According to the chart in the factory service manual, the low resistance should be encountered if the intake air temperature is at extreme temps ~250F. At my garage temps, about 50F, I should be reading 3-4K ohms.

Make sense to everyone? I wish I could post the page for the service manual to help next time someone is troubleshooting the same conditions. I will post back how this effects my idle when I get my new sensor installed.

Eddie 70

Just installed the IAT sensor. I now have CEL's. Woo hoo!! Now, I have to get my idle back to where the spec calls for. For some reason my throttle when setting at the idle position, the car idles at ~1000 RPM. I loosened the throttle cable so there was no tension on it at all. I loosened the throttle stop and even when it is not touching the car will idle at higher speed unless I push back on the throttle toward the closed direction.

Any ideas on how to correct the idle now?

lazlong

What CELs if any? Is there carbon buildup causing the throttle plate to not close fully? Try cleaning the throttle body with carb cleaner.

Don't know about a fix, maybe somebody has one. Service manual says if throttle valve (plate) shaft has excessive play or binding, or the throttle valve binds at the fully closed position to replace the throttle body.